Manager refuses to provide an Experience letter

Hello members,
I am in a situation where my managers refuses to give me a reference/experience letter and I have planned to apply for express entry, I worked for a Gas station in Canada for almost 7 months n have to went to India for some urgency n when I came back my previous manager left that station. Now the new and the old manager both refused to give me the experience letter, But I have my job offer n the letter in which they mentioned my job tittle when I went to India like a leave letter signed by my old manager. I have another one from new manager when I was stuck in India due to flight Ban, he sent me the another one in which he mentioned that Immigration n authorities would allow me to travel without any restrictions for the smooth working of their stores and also have the job tittle on it. I have a link with one of my Colleague who also left the job n move to another province but he is willing to give me a reference letter about my job duties n responsibilities. I am very tensed that would it be work or not?
Please help me and advice me the best way to tackle with this situation.
Thanks in Advance