Please don't think that a punting phone, purchased over the counter with cash is completely untraceable.
A while back when doing jury service, (case was not punting related) there was a burner phone involved. This phone was purchased with cash at a high street store.
Following investigations part of the evidence given was cctv footage of the accused purchasing said phone, which was traced via its imei number, which was linked to the phone number. I was amazed at the amount of intel they had.
Whilst I accept people's punting activities won't attract the level of investigation the case I was on did, and punting phones are 100% the safest way to go, from a punting perspective, please don't think they, even with cash all the way is totally untraceable.