A. If you are being billed for unreturned equipment, first check your account for any return instructions or deadlines. If you have returned the equipment, keep the shipping receipt as proof. If you haven't returned it yet, follow the return process outlined by Fastweb as soon as possible.

B. Contact customer service with your proof of return (if applicable) and request a review of your billing statement. Be prepared to provide details about the return, including tracking numbers and dates.