Charging me for 200mbps line while I am getting 19mbps is it legal?

It has been months when I noticed my internet speed was way too slow, and ever since I have been in contact with them to sort out my line speed as I am paying for 200MBPS and I hardly get 19mbps on average. The first ticket they created for me was the OpenServe line was showing a speed of 100mbps, weeks gone by and still no answer on that, I never got any reply from the guy was talking to my via email, called numerous times and never had a chance to speak to the same person, sent email to the CEO about it, no luck. Now, I exhausted all my avenues and left with no option other than posting a review here and hoping to get this issue resolved. One last thing I wanted to hear from a legal perspective, if they are charging me for a 200mbps line and I am not getting I am paying for, by law, can I get my refund for the access money I have been charged for?