Dear friend,

Please check if it is appropriate if i wirte a thank you letter(e-mail) to a client from whom i've recived payment.

Dear Madam,

thank you so much we've recived the payments & would be glad to assist you in your future commitments

OR

Dear Madam,

thanks for the payments. hope that we recive good business from your side in future
.
Dear Ms [surname],

Thank you very much for your payments received. We will be happy to assist you again in any future business.
Sincerely yours,