Afrihost and Rain is useless

I have an isp account with Afrihost using Rain. The last three months i am having connectivity speed issues. After numerous emails and then changing this setting then changing that setting it still does not work. I have 4G. Connection on the router but i cannot even open google. Their resolution is to go over to Telkom Fixed Wireless bit then i have to pay in money to be able to change. This is unacceptable my internet was working fine and niw i cannot do anything with it