I worked in a bank about 20 years ago and accepting coins, foreign or otherwise, was never a problem. As Westside says, it was a bank.
Then someone decided that actually we're not making any money from counting coins and hauling them around the office. We could be spending the time much better selling crap financial products and dodgy insurance. Funny enough that didn't go very well.
And just in case anyone has any doubts, banks are run by a bunch of greedy bastards who just want to screw you for every penny you've got. As long as they don't have to count them.
2014 in Northern Ireland:
Number of reported attacks on sex workers 70
Number of sex trafficking cases ZERO