Can a company hold back salary if target is not achieved and while on PIP period?

So basically i have worked in a company for 1 month as a BDE according to my offer letter i had to do 50% of my sales target and mandatory 3 sales if am unable to do so i will get my salary but with certain deduction but this scammers put me in the PTB period which is a performance boost period and asked me to complete my sales target or else they won't pay me my salary. It was written no where that if am unable to achieve my target i won't be paid a single penny plus according to my knowledge if we are kept on PTB or PIP period our salary is paid and we are given certain time to boost our performance if we are unable to do so the company has full right to terminate us. But this scammers didn't even pay me my salary and wants me to work another month for free and pay me the salary only if i complete my target.I kept on asking them from the beginning about what will be the deducted amount if am unable to achieve my target they never told me. So i just want to know is it legal to hold back salary during the PIP period and it was not written in my offer letter that i will not be paid a single penny if am unable to achieve my target. Please kindly help me.