Bribery
noun

the crime of giving someone money or something else of value, often illegally, to persuade that person to do something you want:
(Cambridge English Dictionary)

Your case:
paying tc/USD (the crime of giving someone money or something else of value to persuade...) for unban ( ... to do something you want)

Main point you might take it to the light : "... , often illegally, ..." often means frequently but not always the case . In this case we can also include this to bribery even though giving tc/ money here does not count as illegal thing.

I don't know other words that fit this case other than bribery