what happens if i sent bitcoin to a clubcoin address (address starts with a C)? what happens if i sent bitcoin to a clubcoin address (address starts with a C)? will i get refunded and get notified the transaction was invalid? please help me!
There are no Bitcoin addresses defined that start with a C (only P2PKH addresses which start with 1, P2SH addresses which start with 3, and P2WSH or P2WPKH addresses which start with bc1).

As a result, it is impossible to even create a transaction to such an address. There is nothing to refund of nofify - it's simply impossible to perform.