Help!Accounts keep getting banned

I have been doing CPA for almost a year now. I used to do on a consistent basis but then i had the problem of my videos getting taken down. I used my own account which was a few months old and didnt have any problem in ranking. I solved that problem by buying aged accounts with vids and had success with ranking a couple of vids but then i started facing the issue of vids not ranking anymore and by each video i uploaded the ranking wud get more worse and worse. I left cpa for a month or so and tried again, no luck. I had left it for quite awhile now busy in life.
I started again in august , didnt upload any cpa vid just bought aged video with videos and uploaded 2 normal clips of a game in an interval of 1-2 weeks each and then left it. I went to upload a video yesterday and found the account blocked.
I have no idea whats going wrong all the time? Am i using the proxies wrongly or what.
Is there any procedure to follow after you use each new account?Can someone please help