Presumably, the question is asking how many times a tennis ball has been struck while tethered to a device, similar to a tether ball. If that is the case, then no such record exists, at least according to the Guinness World Records Online (refer to the link, below).
by. harper maffei
i bounced the ball 2,000 times in 5minuts
26 hours, by a teacher
YES THIS IS TRUE
How high you can bounce it or how long you can keep on bouncing?
17 hours 24 minutes
Cock and balls
The longest time for bouncing a ball is 17 hours 24mins.