Termination without pay and notice

Dear Sir/Madam, I have been terminated by my employer without any notice, i was verbally told i will be paid 20 days of salary but was only paid for 15 days . My offer letter does not have any terms with respect to notice period or termination. This said 1) I have not received any communication from my employer on my performance, company performance or the reason why i have not been paid my variable pay, i have sent them an email asking them for the same 2) I was not give any notice and was asked to leave immediately after finishing off my pending work which took 5 days, i was verbally told i would be paid 20 days of salary however i was paid only 15 days I need advice on whether i can pursue this case in court since my variable pay has not been given out and this amounts to a huge sum. Many other employees have been given 100 % payout of variable pay. There are no clauses defined for the pay out of variable pay except a mention of it depending on mine and company performance