You cannot do anything I'm afraid, as soon as you get a limit, this cannot change even if you contact the customer service. It's the risk department's decision.
Even if you delete your current account and create a new one after some time, the betting companies keep a record of your details, you'll get the same limits from the beginning. That's the good scenario, the worse is to let you bet as long as you lose money and if you win they will give you back only the deposit using one of their T&Cs.
