you have insufficient data to determine what is wrong. However, if you throw money at it and just keep replacing parts, eventually you may get it.
Does this have an intermittent wiper function?
Does it start/stop randomly or at a regular rate?
Does it stop in the middle of a cycle?
Does it do it when standing still or only when driving?
If when driving, is it affected by bumps in the road?
Did you purchase a relay specifically for you car?
A bad connection or defective relay would be indicated if it is when driving and especially on rough roads and in the middle of a cycle.
A defective switch might be indicated if fitted with intermittent function and it stops at end of cycle.
If it is a generic relay, your car may not even use a relay and that would indicate you have a defective control board.