Your question asks about the use of the plural pronoun our to refer to the company.
The use of plural pronouns to represent collective nouns—such as company, team, division, department, or unit—works fine to emphasize the individuals in the organization.
- Business Writing
They provide the following examples (emphasis in original):
- We at Company X wish to express our sincere appreciation for Company Y’s continued support.
- Brooks & Rice have lost their lease. They are now looking for a new location. (citing Gregg)
The link goes on to cite The Gregg Reference Manual, The Chicago Manual of Style, and The Associated Press Stylebook to support both singular and plural agreement in these situations.
You can think of the company as the collection of individuals it represents (whether shareholders, directors, officers and/or staff, etc). It's this collection that asserts the lack of a guarantee in your example. Since the writer is writing on behalf of the company, using a first-person pronoun works.
On the other hand, you are also free to consider the company as a monolithic 'individual', so calling the website 'its website' as you propose is also ok. In that case, however, you need to be careful to distinguish whether 'its contents' referred to later are the company's contents or the website's contents.
You should, however, be consistent - either "provide ... our" or "provides ... its", but not "provides ... our". The link above notes this with the following problematic example (the asterisks below denote a problematic portion - both should be singular or both should be plural):
- Company X *wishes to express *our sincere appreciation for Company Y’s continued support.
In my opinion, "Company X wish" sounds decidedly odd. I'd prefer either "We at Company X *wish" or "Company X wishes ... its".