Want to change to cheap network. Currently using Mint

I have been using Mint for a year now, and the network is very bad where I live right now. It’s almost 0 network.

I want to change to a cheap network, as I also have a WiFi at home.

Which network would you suggest me. Want to pay monthly. Or 3 months.

Only, if I go out, there I network which is annoying and I have been missing calls from friends because of this.

Your help is appreciated.