please could someone give me the number to ring to report a malfunctioning digi card (card error 50) yes i have tried cleaning the chip to no avail. or a link to the subject on here. Ta!
Replacing lost, stolen or faulty driver smart cards
Your digital tachograph smart card is valid for five years. However, if it is lost, stolen or stops working, you must have a new card issued for the rest of the five-year period.
If your card is lost or stolen, you must report it to Driver and Vehicle Licensing Agency (DVLA). You will need to phone the DVLA Tachograph Smart Card Helpline on Tel 0300 790 6109 to request the replacement card and pay a £19 fee by credit or debit card.
Alternatively, you can complete an application form and send it with the relevant fee to:
DVLA
Swansea
SA99 1AZYou will need to apply for the replacement within seven calendar days.
Faulty cardsIf your card is faulty you will need to return it with a completed application form to DVLA who will issue a new card. You will need to apply within seven calendar days for a replacement.
Where possible try the card in a different vehicle unit (VU) to doublecheck that the card is faulty.
Thank you kindly 
You’re welcome 