My mobile phone is not equipped with Monternet, and I haven't received Monternet messages, but I charge every day. I went to the mobile business hall to ask, and they said there was no way.

It's no use complaining. I guess the mobile phone you use should be a fake version. Fake mobile phones are normal. They all have back doors. If you accidentally order something on your mobile phone, they will deduct the fee. Maybe they think money is tight recently, and it's normal to get it back through the back door.