Dear client,
The situation you have described is complicated and requires a careful examination of the sale agreement and the relevant laws of your jurisdiction. However, I can provide some general information and guidance.
Firstly, the validity of the sale agreement depends on various factors, including whether the seller was coerced or under duress to sign the agreement, the authenticity of the document, and the absence of any legal defects or irregularities. The fact that the seller added the date under his signature raises questions about the authenticity of the agreement. Additionally, the absence of witnesses can also raise concerns about the validity of the agreement.
Secondly, if the money lenders have altered the date on the agreement, this could be considered as tampering or forgery, which is a serious legal offense. You may want to seek the assistance of a legal expert to verify whether the document has been tampered with and to advise you on the next steps.
Thirdly, in terms of remedies, you could potentially seek a specific performance of the sale agreement or damages for breach of contract. However, this will depend on the specific laws of your jurisdiction and the specific circumstances of your case.
In any case, it would be wise to seek the assistance of a qualified legal professional who can help you navigate this situation and protect your interests.