The country code for the United Arab Emirates is +971, and you must omit the trunk prefix 0 from the UAE number.
(The plus sign means "insert your international access prefix here." From a GSM mobile phone, you can enter the number in full international format, starting with the plus sign. The most common prefix is 00, but North America (USA, Canada, etc.) uses 011, and many other countries use different prefixes.)
You should ask yourself, "Who are my readers?"
No reason why there should be no cell phones in Thailand
You should write it in full in any formal or academic writing.
audience
Not sure, but you should probably learn to spell 'writing' before you begin.
Yes, liposuction to the chin or "double chin" area is performed in Thailand. Those considering this surgery should discuss with their doctor to make sure other alternatives would not work before considering surgery.
topic, audience, purpose and details...
Create a short outline for your response.
Before you write
Before you write the rough draft
Who your readers are and what they know
You should brainstorm a lot of ideas. Also, look through a bunch of books to get ideas for the novel. Here are some links to help you learn more about writing.