connection problem

I Don't know what is going on. Its been a week now and I still struggling with poor connection. I tried to talk to the on facebook messanger then they reply that they will look into it. I tried on whatsapp then they say they see that there is no problem with the connection. they install the external modem a few months back. and how they install it we left it as it is. its every last week before payday we struggle with connection. Last time when we phone them they said that there was a problem with the tower... excuses excuses excuses.. they don't care to keep the customer happy. as long as they can get their money then they are happy. they don't say ok sorry about the inconvenience we will sort the problem out and for an example 1 day discount on payment... no they want full payment if we struggle or not. i see there is lot of people on facebook that's looking for a service provider but how can I tell them about rain if I get poor service from them. when we get rain the first time we didn't have any issues. But as time goes by we getting no connection or struggle with connection. If there are no problem with connection like they say then why do we struggle with connection. especially with an external modem