I am sorry to have caused you so much trouble/hassle.

[Jit833]

1) I am sorry to have caused you so much trouble/hassle.
2) I am sorry to keep hassling and troubling you.
3) I am sorry for the trouble and hassle that I have caused you.

Can I say the above sentences in such a way?

 

[probus]

"I am sorry to have caused you so much trouble" is correct and formal.

"I am sorry to have given you so much hassle" is also correct but less formal. Hassle is almost a colloquialism, in my opinion. Because of their differing degrees of formality, I would not use both trouble and hassle in the same sentence.

 

[Jit833]

Thanks for teaching me probus. You have been such a great teacher.