Debt collection laws exist to protect personal consumers from unfair and illegal practices employed by debt collection agencies or their agents. There are very strict rules in place regarding how you can be contacted, at what times and where. The financial institutions cannot just walk over your rights and if they do, they can be fined and taken to task by the relevant authorities.
You can stop all contact if you wish by simply writing to your creditors and invoking your rights under the Fair Debt Collection Act. However, this doesn’t make your debts go away. Only paying them off will do and it is something you should look at carefully before the situation gets out of hand.