Salary related

Hi Sir, I have worked in a company from May to Aug`17 and within the period I have not get salary on time although received in installments by different bank accounts by employer and after getting my approximately salary I have resigned from the company with immediate effect . Now the employer is asking me to give back one month salary and saying that was given from another account and it was a loan but that time we do not have any discussion like this. as I have company`s laptop only with me ( where I already send all the data on mail ) and I already told them that I will give your laptop but after getting my clearance and f & f settlement letter with the payment . So now my question is:- 1. as company is not paying any employees F & F and also not paid salary to me on time so are they eligible to deduct my notice. 2. I am ready to return their asset but not sure about F & F will happen or not. 3. Also not sure about clearance certificate. So you are requested to please guide me on the same. Regards,