Need to reach Bangkok starting Sunday:which is the best solution as in 4 days overstay?Will clear after Labour day holiday.By bus or plane?

From where ?

You have several options depending where you are.

Car,bus,taxi,minibus,aeroplane,train,ferry,motorbike,tuk tuk,song thaew,sam lor,bicycle.

Sorry,you right:Phuket.The best solution,i mean,for avoid to be caught on the way

Sorry,you right:Phuket.The best solution,i mean,for avoid to be caught on the way

If you want to reduce risk then take an internal(domestic) fight from Phuket to Bangkok.

If you do not have a compelling reason to go to Bangkok, the safest solution would be to fly Phuket -> Kuala Lumpur, and then to Kota Bharu if you want to apply for a tourist visa. Kota Bharu Thai consulate is open Monday unlike almost everywhere else.

When did the overstay start?

There are many options to avoid an overstay. Applying for a 7 day extension at immigration is a good option. If eligible a border hop for a visa exempt entry is another option.

When on overstay the least risky option is to travel by air.