I need a Payment Gateway Website Maintenance Developer

General information for the website: I need someone to take up my website maintenance for 3months renewable contract
Kind of development: Customization of existing website
Description of every page/module: We have a payment gateway newly finished, so I need a good developer to maintain it.

In the first 1-3 weeks you, will have to implement some minor updates on site features (see attachment), modify payment release system, maintain email alert system and convert site to responsive.

Some other minor requirements may follow, so be alert.
Description of requirements/features: If you can't fit in my requirement, do not submit a proposal

1. The requirement in the attachment are updates on the website to be completed in the 1st 3days.
2. Modify payment released from same day release to 14days default release, must be completed in 2days
3. Tester are constantly testing site, so you must be able to update solution to bugs within 24hours.
4. Convert the website to responsive, must be completed within 3-7days.

Other quest will come in respectively.

Remember, site is fully functional, we only require modification

We will offer to pay $400per month for initial 3months.
Contract subject to renewal on PPH only. We will not renew the contract outside PPH.

BID will be for an offer of $1200, you must set mile stone of $400 every month.
You will start on 15th of April.

1st milestone is 15th May,
2nd milestone is 15th June,
3rd milestone is 15th July.

I will not release any money until milestone is reached. Moneys will be held with PPH
Extra services needed: Domain, Customization, 3rd party integration, Optimization
Extra notes: We will offer $1200, you must set milestone one third, e.g $400 every month.
You will start on 15th of April.

1st milestone is 15th May,
2nd milestone is 15th June,
3rd milestone is 15th July.

I will not release any money until milestone is reached. Moneys will be held with PPH