What CRM would best suit my small company?

First of all: Sorry for the poor English and explanations, I'll try my best to explain what I need.

The company I work for has 7 employees (5 + 2 part-time) of which maybe 3 would use CRM.

We have around 300 clients all over the country and I need an easy way to do these things:

1. Collect all their information – Company names, phone numbers, emails, addresses, cities, names, etc. I also need a way to sort all of this data, to see clearly which data I am missing from which companies and why.

2. See if they paid their invoices, did they pay their monthly subscriptions to our service, and is everything A-ok in a financial sense. To be able to give them a free subscription month, increase their subscription, etc.

3. We are enrolling updates, usually by hiring someone to drive across the country and install new software on their devices, so we need to keep track of who's updated and who's not, and when is someone due. And an easy way to write this, that would be faster than just using excel as we do it right now.

4. Maybe a fast way to email all of them, text message all of them, send automatic messages that their subscription is due at XYZ time. Basically, anything that makes communicating with them faster.

5. Something that makes solving the issues that they have faster, also something that potentially tracks all the issues our customers face and that compiles all of that in a list so that we can see the frequency of the issues and focus on solving them for good. Maybe even use that to create a support guide for new people that we'd potentially hire. (this would be the most important thing actually)

And so much more.

So essentially, TLDR: track their info and collect missing pieces, track subscriptions, payments, track due updates and servicing, make communication faster and easier, and most importantly, track the issues that they're facing so that we could collect it all and find solutions for them once and for all.