Home internet problem

[wireless]

I moved my home internet to a new address in early January. My problems started from then. At first, the internet speed was very low, and a technician came and solved it, but since then, I have problems accessing many sites and applications, and my internet line is limited. I have called several times and they have checked everything but the problem has not been solved. Unfortunately, it is not possible to chat with the agent for home internet, and there is no place on the site to find a technician who can solve the problem except for a phone number. The last agent I called said that the problem is with the modem and was supposed to send me a modem in 5 working days, but now 10 days have passed and I have not received the new modem. Does anyone know what I should do?

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