As other members have pointed out, unless you furnish the facts completely, you are unlikely to get the right response.
Condition 1: Canteen as Workplace Extension
As a member has pointed out, if the canteen is run inside your company premises, it will be considered an extension of your workplace.
Condition 2: Timing of Injury
It is unclear from your statement whether you suffered the injury during a lunch break (as lunch break is sandwiched between the working hours of the day). If you have suffered an injury during your lunch break, it will be treated as an employment injury provided Condition 1 is satisfied. However, if it has happened either before or after the scheduled lunch break, the reasons for your being there need to be explained appropriately.
Condition 3: Employee Compensation Act vs. Personal Accident Policy
The difference between the Employee Compensation Act and Personal Accident Policy is that the Employee Compensation Act confines to injuries suffered in the course and out of employment and includes notional extension, whereas Personal Accident Policy coverage extends 24 hours worldwide and does not limit injuries suffered in the course and out of employment. In other words, it covers injuries suffered due to an accident on a day off even outside the work premises.
Hence, if you pose your question suitably, members will respond appropriately.
Regarding Financial Matters
Regarding the amount deposited by your boss, you may have to check it out with him, as he would have extended timely help with his personal resources.
Regarding the reimbursement of the amount from the company, the right source will, of course, be your HR department.
Regards