Google Merchant Troubleshooting

I have Google Merchant setup and it was correct until we added some variants to our product and some prices to them. at this moment we have several issues that cause disapproval of our products in Google Merchant.
The issues include:
- Missing attribute [availability date]
- Mismatched value (page crawl) [price]
- Incorrect value [identifier exists]
and some others.
I need someone who can solve these issues for me.