Is it possible to contact DLA and end the benefit from a certain date and pay back any money since then, simply because you no longer wish to receive it any more?
Yes, you can terminate your claim at any time, just write to the DWP office dealing with your claim.
If you are doing so because you believe you no longer meet the criteria for a PIP award then expect some push back from the DWP as to when this actually happened.
Gordon
Nothing on this board constitutes legal advice - always consult a professional about specific problems