Health Insurance In Los

In the UK it is normal to pay for your private health insurance/life insurance by a monthly fee.

However, the private health insurance companies that I have contacted in Thailand have all insisted that I pay by an annual lump sum, about 70,000 baht.

I'm unwilling to do this. To be honest, I simply don't fully trust these companies and don't want to hand over one year of premiums upfront. I prefer to pay monthly and if there is a disagreement over their service etc, then my future premiums are still in my bank account

Does anyone know of a private health insurance company in LoS who accepts monthly premium payments?

Thanks - Simon