Hi BuzzardBoy, I have every sympathy for your plight when people look at your ADR certificate, but the simple answer is that they MUST accept your certificate as being perfectly valid.
The easy answer to your question is to say that SQA were spot-on with the answer they gave you.
The following is written in the knowledge that I know you do international work, meaning that we can totally ignore the UK dangerous goods Regs, because ADR applies “door-to-door” in full, apart from any period you spend on a ferry.
If you’re ever doing ‘UK only’ work, I can come up with a quote that says your ADR licence is still valid for that too. 
Here are the legal reasons for me saying that people MUST recognise your ADR certificate:
BuzzardBoy:
My ADR License is in German, as i took the course in Swiss, although the company that did the course are based in Lichtenstein, so it has an FL country stamp on it, and is in German.
Here is a list of the countries who are contracting parties to the ADR agreement:
……the Contracting Parties are Albania, Austria, Azerbaijan, Belarus, Belgium, Bosnia and Herzegovina, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Italy, Kazakhstan, Latvia, Liechtenstein, Lithuania, Luxembourg, Morocco, Netherlands, Norway, Poland, Portugal, Republic of Moldova, Romania, Russian Federation, Serbia and Montenegro, Slovakia, Slovenia, Spain, Sweden, Switzerland, The former Yugoslav Republic of Macedonia, Ukraine and United Kingdom. [EDIT] To which we can now add: Eire.
BuzzardBoy:
Now, i would like to, if possible exchange it for an English ADR license, as it does draw some strange looks when you present it to people when loading ADR, as they cannot understand it!!
TBH mate, I can’t understand how/why the loading people can’t understand your ADR certificate, because it was correctly issued by the Competent Authority of a contracting party to ADR. In the next quote, you’ll see that the ADR certificates are standardised, to avoid exactly the problem you’re describing…
8.2.1.8 All training certificates conforming to the requirements of this section and issued in accordance with the model shown in 8.2.2.8.3 by the competent authority of a Contracting Party or by any organization recognized by that authority shall be accepted during their period of validity by the competent authorities of other Contracting Parties
Due to this quote, the format and layout of your ADR certificate is provided in ADR, the UN class numbers are the same, as is whether (or not) you’re qualified to drive a tanker.
Anything with a cross covering it means that you can’t do it.
8.2.2.8.3 The certificate shall have the layout of the model below.
Your ADR certificate is written in German, which isn’t actually a problem, because ADR covers ‘strange’ languages in the following way:
8.2.1.9 The certificate shall be prepared in the language or one of the languages of the country of the competent authority which issued the certificate or recognized the issuing organization and, if this language is not English, French or German, also in English, French or German…
I might have some sympathy if the loading people had to read an ADR certificate that’s written in Russian, but guess what?? The format and language requirements are covered above and Russian numbers are the same as ours, so we’d know exactly what a Russian driver could or couldn’t carry on a vehicle.
I’ve gone into some depth of detail on this, because I hope it avoids you thinking that you might have to enrol on an ADR course in the UK, whilst you still hold a perfectly valid ADR certificate.
There might then potentially be an additional issue depending on which country issued your driver’s licence.
I hope this helps. 
