A company that I had previously had a subscription with and cancelled continues to charge me, so I contact their support team and they say that their system shows me to be cancelled. They have asked me to give the first 6 digits and last 4 of my credit card over email after a long back and forth. Is this safe details of my credit card to send or should I do it phone or perhaps just contact my bank. The company is SCRIBD, a reading service btw.
No, you shouldn't. Due to too many data leaks, even sending a part of the credit card number is not safe.
Due to USA poor electronics subscription regulation, one who wants to cancel the Scribd account online need to go through a series of deceptive option screens. IMHO, you should just go back to your Scribd account and reinspect the cancellation process, make sure you don't miss every step as pointed up by the article given (note: interface might change since the article is written in 2015).
If this doesn't work, it is easier to call your credit card company to revoke the consent or get a new card.
In Poland such things are called "soup made on nail". A deception that make you believe the other side have all the ingredients and you just need to provide small detail. While in fact they have none and you provide them with everything but they leave the impression on by veryfing "they have it" by giving you back what you just told them.
- Credit card numbers have 16 numbers. You give them 10 of them. Of which 4 are the last ones. Next time they could say "If you are owner of the card ending in 1234 please provide Next to last 4 numbers".
- If they are billing your CC they already should have your CC number. Veryfing you based on those number WOULD be ok if there was trust in that company. In your case I'd say there is none so I would avoid such method of verification.
In general, if cancelation of any payment is fruitless on the vendor side I just go straight to my bank and cancel/block payment there. It's the same work as going through identical process on vendor side (of which I know don't work).