If your account has been hacked, and even possibly misused, the company would be well within its right to take the time to verify everything you say. They wouldn't, after all, want to fall foul of the law in any manner and be liable for something illegal. That said, check the consumer laws in your country - In mine (India), when I wish to file a complain and send such notices to a company (informing them to resolve the issue or else be dragged to court), I generally have to give them a "reasonable" time to resolve the issues (around 15 to 30 days). (And yes, if the company has stopped communicating you, send them such notice / demand immediately so they will have to respond to you - nothing gets a company moving faster than unnecessary legal expenditure and being summoned in court. If they have an office in your country, they are bound by your country's law). (For more on the legal aspect, ask in law.stackexchange.com and consult an attorney).