Stayed in Thailand for 3 months and did another border bounce at the same location , this time paid an agency 4300 Baht for guaranteed entry.
Went straight into Lao and back again and got stamped into Thailand with no questions asked .
Asked the immigration about doing the same visa run again and they said they will only do two consecutive land border crossings and so next time I will have to fly in .
Worked out that they would be pocketting 240 000 Baht a month from this entry service