Client not sending contract

So I have been working as a freelance designer for a while. All the companies I have freelanced for have always been very professional. They sent me contract of our agreed agreement and then only started the work.

Now there comes this annoying client, We agreed on x hourly rate and I was going to raise an invoice at the end of every month.

Now I have been working for him since mid of August and after telling him at least 3-4 times for contract he’s still not sent it.

I could not raise an invoice last month because of that and even the work was around 10-14 hrs only so I thought I’ll combine it with this month’s invoice and then send it. But he still hasn’t sent me the contract and shamelessly he’s giving more and more work.

Question: What is the standard protocol as a freelancer regarding contract?

I have been quite lucky to always find clients who did the contract properly before I start work but this one is so annoying I have no idea what to do. Also he and his company is so confused, they keep changing their requirements frequently, he wants me to be available/online all the time but he’s only an hourly client.