You still can submit your application. They will probably start to review it from 3 feb. Or maybe it will be reviewed by some staff from an other embassy to avoid too long delays.. Who knows...
i read this story a few days ago and it made absolutely no sense. There is no "entry fee" in Thailand, but this is right that you are technically required to present to the IO proof of funds amounting to 20,000 THB or its equivalent in cash.
The rule is 180 days per year in Thailand, it doesn't change anything if they are consecutive or not, it is cumulative. However, the UK signed a DTA with Thailand to avoid double taxation, i suggest you take a look on it.
i think you make a mistake with the rule that IO can ask to see 20.000 in cash in order to let a visitor into the country. (to prove they can support themselves) It is not a "fee".
based on which ground this fee is supposed to be paid ? It is clearly written at the airport to not give any money to IO's. This story seems fishy to me.