The gold associated with your account is separate from the company's other assets. An independent trustee acts on your behalf, and the gold/silver linked to your account is held by a custodian. When you request delivery, the required quantity is removed from the custodian and delivered to you.
Because the Security Trustee has a charge over the gold, any issues at the company level will not affect the gold linked to your account. The title of the gold clearly rests with you, and the physical gold/silver stored with the Custodian is not an asset of the company.
This structure is similar to a Mutual Fund, where the AMC and the assets of a particular scheme are kept separate.