We're lucky, there is a permanent promotion of 0.1% cashback at MadMARKET on all bets placed via their Edge software.
I think you have to take it at registration, because I don't see the option afterwards, but you can try asking support.
Here is the link:
0.1% cashback promo page- Here is the offer
Here is the offer
Here is the offer - cashback-madmarket.jpg (80.48 KiB) Viewed 3564 times