How to organize high-speed Internet access for a small office?

Question

Computer networks

Hello!
There is a branch office consisting of 12 people.
Now Yota is used there
From Iota, everything diverges by switches, and everything works pretty quickly and stably.
But!
1) Once the BS fell and there was no Internet for three weeks.
2) New people come and the office grows
Question.
1) How can I organize uninterrupted network operation on wireless Iota? (local Internet costs 60 tr per month)
2) How to organize high-speed access? (well, of course, don’t download torrents, but a couple of Mbps per person are normal)

Answer 1

Increasing the number of points is unlikely to solve the problem, the tower also has a limit.
Internet in the office without a wire is not an Internet !!! Another question is that the wire can come "through the air".
In my practice, there was a case when we agreed with a granny from the house opposite and just threw a radio channel from her over a waffle.

Answer 2

In addition to Iota, not a single mobile operator? Well, or Wi-Fi if there is a point-to-point from where.
Something like this