1. Before Tina left, Mandy demanded Tina to pay the total price of $120,000, Tina was surprised and asked why it was so expensive. Mandy explained the mesotherapy treatment Tina has taken by showing her Tina the agreement she signed. After paid $50,000 of all of the cash she had on hand, Tina asked to leave to draw money from the ETC machine but never showed up. 
2. After returned back to China, Tina found that the Botox on the lower face and SUB Q Hyaluronic Acid/Tissue Filler/Vital Light were solely applied for beauty treatment, nothing to do with her eye wrinkle, eye circles or whitening. 
3. On the following days, Toby whatsapp Tina for the payment of the outstanding balance whereby in reply Tina claimed that she has determined to terminate the contract as SB had misled or deceived her to take the beauty treatment which she has never agreed. She was only liable for the Botox on the upper face and the REDENSITY for eye circles and wrinkles and counterclaimed SB to refund the payment of $25,000 = [$50,000 - ($5,000+$20,000)] on the ground that SB has breached the Trade Description Ordinance Cap 362 in offering the beauty treatment to her on that date of contract as at material times she is a  psychiatric patient and did not have the capacity in entering the contract with SB. Further she was misled in entering the mesotherapy agreement. The contract was void and SB should refund back the payment of $50,000 to her.
4. SB took the action against Tina. 

Advise Tina whether Tina is liable to pay SB the balance of payment or she is entitled to counterclaim for the refund of $25,000.

1. Explain the importance of the essential elements required for the formation of a valid contract in this scenario.

2. Apply the relevant elements of contract in the context and advise whether a contract is formed between Tina and SB