The choices that you have are:
Have your agent contact the other agent verbally to get it moving forward.
Send an ammendment indicating that if can not get in property you will place the seller on notice of defect
Send notice of defect , this notice needs to be sent prior to the expiration of time frames outlined in your contract. This will kill the deal if done withing the time frames.
Again discuss this with your agent. If the seller does not want you to inspect you need to be concerned. Your agent may have other approaches to address the issue but watch out for the time frames in the contract.
First Weber Group
Certified Distressed Property Expert