As someone who has actually handled Midland files, let me give you some advice.
Firstly, if its not your, they will not fight it. They have nothing t gain, they will lose almost by default.
Here is what I would do:
First, if it is reported on your credit, write a POLITE letter to the three credit bureaus stating you dispute the debt. The collector is required to respond to a challenge within a certain period of time. If they cant prove it, then the debt will be removed from your credit.
Secondly, write a letter to the collector stating that you want Verification of the debt, and that you dispute it. Make sure to ask for the original signed contract. They will send you a copy of a statement, and the original docs if they exist.
Thirdly, be patient. It will take at least a month, and it can often take a few months to get something to come off your credit.
If you really want to screw with them, get them to break the FDCPA. Not only will they have to get rid of your debt, they will have to pay you. They typically lose my default. The company I worked for could not sue anybody in an entire county because of ONE lawyer who kept counter suing them. Just ONE lawyer, and an entire county was spared.